michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  *
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: #include "nsCache.h"
michael@0: #include <limits.h>
michael@0: 
michael@0: #include "nscore.h"
michael@0: #include "nsDiskCacheBinding.h"
michael@0: #include "nsCacheService.h"
michael@0: 
michael@0: 
michael@0: 
michael@0: /******************************************************************************
michael@0:  *  static hash table callback functions
michael@0:  *
michael@0:  *****************************************************************************/
michael@0: struct HashTableEntry : PLDHashEntryHdr {
michael@0:     nsDiskCacheBinding *  mBinding;
michael@0: };
michael@0: 
michael@0: 
michael@0: static PLDHashNumber
michael@0: HashKey( PLDHashTable *table, const void *key)
michael@0: {
michael@0:     return (PLDHashNumber) NS_PTR_TO_INT32(key);
michael@0: }
michael@0: 
michael@0: 
michael@0: static bool
michael@0: MatchEntry(PLDHashTable *              /* table */,
michael@0:             const PLDHashEntryHdr *       header,
michael@0:             const void *                  key)
michael@0: {
michael@0:     HashTableEntry * hashEntry = (HashTableEntry *) header;
michael@0:     return (hashEntry->mBinding->mRecord.HashNumber() == (PLDHashNumber) NS_PTR_TO_INT32(key));
michael@0: }
michael@0: 
michael@0: static void
michael@0: MoveEntry(PLDHashTable *           /* table */,
michael@0:           const PLDHashEntryHdr *     src,
michael@0:           PLDHashEntryHdr       *     dst)
michael@0: {
michael@0:     ((HashTableEntry *)dst)->mBinding = ((HashTableEntry *)src)->mBinding;
michael@0: }
michael@0: 
michael@0: 
michael@0: static void
michael@0: ClearEntry(PLDHashTable *      /* table */,
michael@0:            PLDHashEntryHdr *      header)
michael@0: {
michael@0:     ((HashTableEntry *)header)->mBinding = nullptr;
michael@0: }
michael@0: 
michael@0: 
michael@0: /******************************************************************************
michael@0:  *  Utility Functions
michael@0:  *****************************************************************************/
michael@0: nsDiskCacheBinding *
michael@0: GetCacheEntryBinding(nsCacheEntry * entry)
michael@0: {
michael@0:     return (nsDiskCacheBinding *) entry->Data();
michael@0: }
michael@0: 
michael@0: 
michael@0: /******************************************************************************
michael@0:  *  nsDiskCacheBinding
michael@0:  *****************************************************************************/
michael@0: 
michael@0: NS_IMPL_ISUPPORTS0(nsDiskCacheBinding)
michael@0: 
michael@0: nsDiskCacheBinding::nsDiskCacheBinding(nsCacheEntry* entry, nsDiskCacheRecord * record)
michael@0:     :   mCacheEntry(entry)
michael@0:     ,   mStreamIO(nullptr)
michael@0:     ,   mDeactivateEvent(nullptr)
michael@0: {
michael@0:     NS_ASSERTION(record->ValidRecord(), "bad record");
michael@0:     PR_INIT_CLIST(this);
michael@0:     mRecord     = *record;
michael@0:     mDoomed     = entry->IsDoomed();
michael@0:     mGeneration = record->Generation();    // 0 == uninitialized, or data & meta using block files
michael@0: }
michael@0: 
michael@0: nsDiskCacheBinding::~nsDiskCacheBinding()
michael@0: {
michael@0:     // Grab the cache lock since the binding is stored in nsCacheEntry::mData
michael@0:     // and it is released using nsCacheService::ReleaseObject_Locked() which
michael@0:     // releases the object outside the cache lock.
michael@0:     nsCacheServiceAutoLock lock(LOCK_TELEM(NSDISKCACHEBINDING_DESTRUCTOR));
michael@0: 
michael@0:     NS_ASSERTION(PR_CLIST_IS_EMPTY(this), "binding deleted while still on list");
michael@0:     if (!PR_CLIST_IS_EMPTY(this))
michael@0:         PR_REMOVE_LINK(this);       // XXX why are we still on a list?
michael@0:     
michael@0:     // sever streamIO/binding link
michael@0:     if (mStreamIO) {
michael@0:         if (NS_FAILED(mStreamIO->ClearBinding()))
michael@0:             nsCacheService::DoomEntry(mCacheEntry);
michael@0:         NS_RELEASE(mStreamIO);
michael@0:     }
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsDiskCacheBinding::EnsureStreamIO()
michael@0: {
michael@0:     if (!mStreamIO) {
michael@0:         mStreamIO = new nsDiskCacheStreamIO(this);
michael@0:         if (!mStreamIO)  return NS_ERROR_OUT_OF_MEMORY;
michael@0:         NS_ADDREF(mStreamIO);
michael@0:     }
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: /******************************************************************************
michael@0:  *  nsDiskCacheBindery
michael@0:  *
michael@0:  *  Keeps track of bound disk cache entries to detect for collisions.
michael@0:  *
michael@0:  *****************************************************************************/
michael@0: 
michael@0: const PLDHashTableOps nsDiskCacheBindery::ops =
michael@0: {
michael@0:     PL_DHashAllocTable,
michael@0:     PL_DHashFreeTable,
michael@0:     HashKey,
michael@0:     MatchEntry,
michael@0:     MoveEntry,
michael@0:     ClearEntry,
michael@0:     PL_DHashFinalizeStub
michael@0: };
michael@0: 
michael@0: 
michael@0: nsDiskCacheBindery::nsDiskCacheBindery()
michael@0:     : initialized(false)
michael@0: {
michael@0: }
michael@0: 
michael@0: 
michael@0: nsDiskCacheBindery::~nsDiskCacheBindery()
michael@0: {
michael@0:     Reset();
michael@0: }
michael@0: 
michael@0: 
michael@0: nsresult
michael@0: nsDiskCacheBindery::Init()
michael@0: {
michael@0:     nsresult rv = NS_OK;
michael@0:     PL_DHashTableInit(&table, &ops, nullptr, sizeof(HashTableEntry), 0);
michael@0:     initialized = true;
michael@0: 
michael@0:     return rv;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsDiskCacheBindery::Reset()
michael@0: {
michael@0:     if (initialized) {
michael@0:         PL_DHashTableFinish(&table);
michael@0:         initialized = false;
michael@0:     }
michael@0: }
michael@0: 
michael@0: 
michael@0: nsDiskCacheBinding *
michael@0: nsDiskCacheBindery::CreateBinding(nsCacheEntry *       entry,
michael@0:                                   nsDiskCacheRecord *  record)
michael@0: {
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0:     nsCOMPtr<nsISupports> data = entry->Data();
michael@0:     if (data) {
michael@0:         NS_ERROR("cache entry already has bind data");
michael@0:         return nullptr;
michael@0:     }
michael@0:     
michael@0:     nsDiskCacheBinding * binding = new nsDiskCacheBinding(entry, record);
michael@0:     if (!binding)  return nullptr;
michael@0:         
michael@0:     // give ownership of the binding to the entry
michael@0:     entry->SetData(binding);
michael@0:     
michael@0:     // add binding to collision detection system
michael@0:     nsresult rv = AddBinding(binding);
michael@0:     if (NS_FAILED(rv)) {
michael@0:         entry->SetData(nullptr);
michael@0:         return nullptr;
michael@0:     }
michael@0: 
michael@0:     return binding;
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  *  FindActiveEntry :  to find active colliding entry so we can doom it
michael@0:  */
michael@0: nsDiskCacheBinding *
michael@0: nsDiskCacheBindery::FindActiveBinding(uint32_t  hashNumber)
michael@0: {
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0:     // find hash entry for key
michael@0:     HashTableEntry * hashEntry;
michael@0:     hashEntry =
michael@0:       (HashTableEntry *) PL_DHashTableOperate(&table,
michael@0:                                               (void*)(uintptr_t) hashNumber,
michael@0:                                               PL_DHASH_LOOKUP);
michael@0:     if (PL_DHASH_ENTRY_IS_FREE(hashEntry)) return nullptr;
michael@0: 
michael@0:     // walk list looking for active entry
michael@0:     NS_ASSERTION(hashEntry->mBinding, "hash entry left with no binding");
michael@0:     nsDiskCacheBinding * binding = hashEntry->mBinding;    
michael@0:     while (binding->mCacheEntry->IsDoomed()) {
michael@0:         binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
michael@0:         if (binding == hashEntry->mBinding)  return nullptr;
michael@0:     }
michael@0:     return binding;
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  *  AddBinding
michael@0:  *
michael@0:  *  Called from FindEntry() if we read an entry off of disk
michael@0:  *      - it may already have a generation number
michael@0:  *      - a generation number conflict is an error
michael@0:  *
michael@0:  *  Called from BindEntry()
michael@0:  *      - a generation number needs to be assigned
michael@0:  */
michael@0: nsresult
michael@0: nsDiskCacheBindery::AddBinding(nsDiskCacheBinding * binding)
michael@0: {
michael@0:     NS_ENSURE_ARG_POINTER(binding);
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0: 
michael@0:     // find hash entry for key
michael@0:     HashTableEntry * hashEntry;
michael@0:     hashEntry = (HashTableEntry *)
michael@0:       PL_DHashTableOperate(&table,
michael@0:                            (void *)(uintptr_t) binding->mRecord.HashNumber(),
michael@0:                            PL_DHASH_ADD);
michael@0:     if (!hashEntry) return NS_ERROR_OUT_OF_MEMORY;
michael@0:     
michael@0:     if (hashEntry->mBinding == nullptr) {
michael@0:         hashEntry->mBinding = binding;
michael@0:         if (binding->mGeneration == 0)
michael@0:             binding->mGeneration = 1;   // if generation uninitialized, set it to 1
michael@0:             
michael@0:         return NS_OK;
michael@0:     }
michael@0:     
michael@0:     
michael@0:     // insert binding in generation order
michael@0:     nsDiskCacheBinding * p  = hashEntry->mBinding;
michael@0:     bool     calcGeneration = (binding->mGeneration == 0);  // do we need to calculate generation?
michael@0:     if (calcGeneration)  binding->mGeneration = 1;          // initialize to 1 if uninitialized
michael@0:     while (1) {
michael@0:     
michael@0:         if (binding->mGeneration < p->mGeneration) {
michael@0:             // here we are
michael@0:             PR_INSERT_BEFORE(binding, p);
michael@0:             if (hashEntry->mBinding == p)
michael@0:                 hashEntry->mBinding = binding;
michael@0:             break;
michael@0:         }
michael@0:         
michael@0:         if (binding->mGeneration == p->mGeneration) {
michael@0:             if (calcGeneration)  ++binding->mGeneration;    // try the next generation
michael@0:             else {
michael@0:                 NS_ERROR("### disk cache: generations collide!");
michael@0:                 return NS_ERROR_UNEXPECTED;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         p = (nsDiskCacheBinding *)PR_NEXT_LINK(p);
michael@0:         if (p == hashEntry->mBinding) {
michael@0:             // end of line: insert here or die
michael@0:             p = (nsDiskCacheBinding *)PR_PREV_LINK(p);  // back up and check generation
michael@0:             if (p->mGeneration == 255) {
michael@0:                 NS_WARNING("### disk cache: generation capacity at full");
michael@0:                 return NS_ERROR_UNEXPECTED;
michael@0:             }
michael@0:             PR_INSERT_BEFORE(binding, hashEntry->mBinding);
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  *  RemoveBinding :  remove binding from collision detection on deactivation
michael@0:  */
michael@0: void
michael@0: nsDiskCacheBindery::RemoveBinding(nsDiskCacheBinding * binding)
michael@0: {
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0:     if (!initialized)   return;
michael@0:     
michael@0:     HashTableEntry * hashEntry;
michael@0:     void           * key = (void *)(uintptr_t)binding->mRecord.HashNumber();
michael@0: 
michael@0:     hashEntry = (HashTableEntry*) PL_DHashTableOperate(&table,
michael@0:                                                        (void*)(uintptr_t) key,
michael@0:                                                        PL_DHASH_LOOKUP);
michael@0:     if (!PL_DHASH_ENTRY_IS_BUSY(hashEntry)) {
michael@0:         NS_WARNING("### disk cache: binding not in hashtable!");
michael@0:         return;
michael@0:     }
michael@0:     
michael@0:     if (binding == hashEntry->mBinding) {
michael@0:         if (PR_CLIST_IS_EMPTY(binding)) {
michael@0:             // remove this hash entry
michael@0:             PL_DHashTableOperate(&table,
michael@0:                                  (void*)(uintptr_t) binding->mRecord.HashNumber(),
michael@0:                                  PL_DHASH_REMOVE);
michael@0:             return;
michael@0:             
michael@0:         } else {
michael@0:             // promote next binding to head, and unlink this binding
michael@0:             hashEntry->mBinding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
michael@0:         }
michael@0:     }
michael@0:     PR_REMOVE_AND_INIT_LINK(binding);
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  *  ActiveBinding : PLDHashTable enumerate function to verify active bindings
michael@0:  */
michael@0: 
michael@0: PLDHashOperator
michael@0: ActiveBinding(PLDHashTable *    table,
michael@0:               PLDHashEntryHdr * hdr,
michael@0:               uint32_t          number,
michael@0:               void *            arg)
michael@0: {
michael@0:     nsDiskCacheBinding * binding = ((HashTableEntry *)hdr)->mBinding;
michael@0:     NS_ASSERTION(binding, "### disk cache binding = nullptr!");
michael@0:     
michael@0:     nsDiskCacheBinding * head = binding;
michael@0:     do {   
michael@0:         if (binding->IsActive()) {
michael@0:            *((bool *)arg) = true;
michael@0:             return PL_DHASH_STOP;
michael@0:         }
michael@0: 
michael@0:         binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
michael@0:     } while (binding != head);
michael@0: 
michael@0:     return PL_DHASH_NEXT;
michael@0: }
michael@0: 
michael@0: 
michael@0: /**
michael@0:  *  ActiveBindings : return true if any bindings have open descriptors
michael@0:  */
michael@0: bool
michael@0: nsDiskCacheBindery::ActiveBindings()
michael@0: {
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0:     if (!initialized) return false;
michael@0: 
michael@0:     bool    activeBinding = false;
michael@0:     PL_DHashTableEnumerate(&table, ActiveBinding, &activeBinding);
michael@0: 
michael@0:     return activeBinding;
michael@0: }
michael@0: 
michael@0: struct AccumulatorArg {
michael@0:     size_t mUsage;
michael@0:     mozilla::MallocSizeOf mMallocSizeOf;
michael@0: };
michael@0: 
michael@0: PLDHashOperator
michael@0: AccumulateHeapUsage(PLDHashTable *table, PLDHashEntryHdr *hdr, uint32_t number,
michael@0:                     void *arg)
michael@0: {
michael@0:     nsDiskCacheBinding *binding = ((HashTableEntry *)hdr)->mBinding;
michael@0:     NS_ASSERTION(binding, "### disk cache binding = nsnull!");
michael@0: 
michael@0:     AccumulatorArg *acc = (AccumulatorArg *)arg;
michael@0: 
michael@0:     nsDiskCacheBinding *head = binding;
michael@0:     do {
michael@0:         acc->mUsage += acc->mMallocSizeOf(binding);
michael@0: 
michael@0:         if (binding->mStreamIO) {
michael@0:             acc->mUsage += binding->mStreamIO->SizeOfIncludingThis(acc->mMallocSizeOf);
michael@0:         }
michael@0: 
michael@0:         /* No good way to get at mDeactivateEvent internals for proper size, so
michael@0:            we use this as an estimate. */
michael@0:         if (binding->mDeactivateEvent) {
michael@0:             acc->mUsage += acc->mMallocSizeOf(binding->mDeactivateEvent);
michael@0:         }
michael@0: 
michael@0:         binding = (nsDiskCacheBinding *)PR_NEXT_LINK(binding);
michael@0:     } while (binding != head);
michael@0: 
michael@0:     return PL_DHASH_NEXT;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * SizeOfExcludingThis: return the amount of heap memory (bytes) being used by the bindery
michael@0:  */
michael@0: size_t
michael@0: nsDiskCacheBindery::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
michael@0: {
michael@0:     NS_ASSERTION(initialized, "nsDiskCacheBindery not initialized");
michael@0:     if (!initialized) return 0;
michael@0: 
michael@0:     AccumulatorArg arg;
michael@0:     arg.mUsage = 0;
michael@0:     arg.mMallocSizeOf = aMallocSizeOf;
michael@0: 
michael@0:     PL_DHashTableEnumerate(&table, AccumulateHeapUsage, &arg);
michael@0: 
michael@0:     return arg.mUsage;
michael@0: }